Aquatic Ecology Aquatic Ecology NotesNotes

SalinitySalinity

The saltiness.The saltiness.

                                                                                                                    

NichesNiches

PhytoplanktonPhytoplankton

Description – small drifting plantsDescription – small drifting plants Niche – they are producers that Niche – they are producers that

support most aquatic food chainssupport most aquatic food chains Example – cyanobacteria & many Example – cyanobacteria & many

types of algaetypes of algae

ZooplanktonZooplankton Description – herbivores that feed on Description – herbivores that feed on

phytoplankton or other zooplanktonphytoplankton or other zooplankton Niche – food stock for larger Niche – food stock for larger

consumersconsumers Example – krill; small crustaceansExample – krill; small crustaceans

NektonNekton Description – larger, strong-Description – larger, strong-

swimming consumersswimming consumers Niche – top consumers in the Niche – top consumers in the

aquatic ecosystemaquatic ecosystem Example – fish, turtles, and Example – fish, turtles, and

whaleswhales

BenthosBenthos

Description – bottom-dwelling Description – bottom-dwelling creaturescreatures

Niche – primary consumers, Niche – primary consumers, decomposersdecomposers

Example – barnacles, oysters, Example – barnacles, oysters, and lobstersand lobsters

Freshwater Freshwater EcosystemsEcosystems

Flowing Water Flowing Water EcosystemsEcosystems

Because of different Because of different environmental conditions in environmental conditions in

each zone, a river is a each zone, a river is a system of different system of different

ecosystems.ecosystems.

Headwater Stream Headwater Stream CharacteristicsCharacteristics

A narrow zone of cold, clear water A narrow zone of cold, clear water that rushes over waterfalls and that rushes over waterfalls and rapids. Large amounts of oxygen rapids. Large amounts of oxygen are present. Fish are also present. are present. Fish are also present. Ex. trout.Ex. trout.

Downstream Downstream CharacteristicsCharacteristics

Slower-moving water, less Slower-moving water, less oxygen, warmer temperatures, oxygen, warmer temperatures, and lots of algae and and lots of algae and cyanobacteria.cyanobacteria.

Energy SourceEnergy Source

GravityGravity

Standing Water Standing Water EcosystemsEcosystems

Lakes, ponds, etc.Lakes, ponds, etc.

Littoral ZoneLittoral ZoneA shallow area near the shore, to the A shallow area near the shore, to the

depth at which rooted plants stop depth at which rooted plants stop growing. Ex. frogs, snails, insects, growing. Ex. frogs, snails, insects, fish, cattails, and water lilies.fish, cattails, and water lilies.

Limnetic ZoneLimnetic Zone

Open, sunlit water that extends Open, sunlit water that extends to the depth penetrated by to the depth penetrated by sunlight.sunlight.

Profundal ZoneProfundal ZoneDeep, open water where it Deep, open water where it

is too dark for is too dark for photosynthesis.photosynthesis.

Thermal Thermal StratificationStratification

DefinitionDefinitionThe temperature difference in The temperature difference in

deep lakes where there are deep lakes where there are warm summers and cold warm summers and cold winters.winters.

CausesCauses During the summer, During the summer,

lakes become stratified lakes become stratified into different into different temperature layers that temperature layers that resist mixing because resist mixing because summer sunlight warms summer sunlight warms surface waters, making surface waters, making them less dense.them less dense.

ThermoclineThermocline The middle layer The middle layer

that acts as a that acts as a barrier to the barrier to the transfer of transfer of nutrients and nutrients and dissolved oxygen.dissolved oxygen.

Fall TurnoverFall Turnover

As the temperatures begin to As the temperatures begin to drop, the surface layer becomes drop, the surface layer becomes more dense, and it sinks to the more dense, and it sinks to the bottom. This mixing brings bottom. This mixing brings nutrients from the bottom up to nutrients from the bottom up to the surface and sends oxygen to the surface and sends oxygen to the bottom.the bottom.

Spring TurnoverSpring Turnover As top water warms and ice As top water warms and ice

melts, it sinks through and melts, it sinks through and below the cooler, less dense below the cooler, less dense water, sending oxygen down water, sending oxygen down and nutrients up.and nutrients up.

Freshwater Freshwater WetlandsWetlands

MarshesMarshesAn area of temporarily flooded, An area of temporarily flooded,

often silty land beside a river or often silty land beside a river or lake.lake.

SwampsSwampsA lowland region permanently A lowland region permanently

covered with water.covered with water.

Hardwood Bottomland Hardwood Bottomland ForestForestAn area down by a river or An area down by a river or

stream where lots of hardwoods, stream where lots of hardwoods, like oaks, grow.like oaks, grow.

Prairie PotholesPrairie Potholes These are depressions that hold These are depressions that hold

water out on the prairie, especially water out on the prairie, especially up north in Canada. It is a very good up north in Canada. It is a very good duck habitat.duck habitat.

Peat Moss BogPeat Moss Bog A wet area that over time fills in (the A wet area that over time fills in (the

last stage of succession is peat last stage of succession is peat moss). It can be very deep. In moss). It can be very deep. In Ireland, they burn this for wood.Ireland, they burn this for wood.

Importance of freshwater Importance of freshwater wetlandswetlands

They filter & purify water.They filter & purify water.Habitat for many animals Habitat for many animals

and plants.and plants.

Historical AspectsHistorical Aspects

Developers and farmers want Developers and farmers want Congress to revise the definition of Congress to revise the definition of wetlands. This would make 60-75% of wetlands. This would make 60-75% of all wetlands unavailable for all wetlands unavailable for protection. The Audubon Society protection. The Audubon Society estimates that wetlands provide water estimates that wetlands provide water quality protection worth $1.6 billion quality protection worth $1.6 billion per year, and they say if that wetlands per year, and they say if that wetlands are destroyed, the U.S. would spend are destroyed, the U.S. would spend $7.7 billion to $31 billion per year in $7.7 billion to $31 billion per year in additional flood-control costs.additional flood-control costs.

EstuariesEstuaries

DefinitionDefinitionA partially enclosed area of A partially enclosed area of

coastal water where sea water coastal water where sea water mixes with freshwater.mixes with freshwater.

Salt MarshesSalt Marshes The ground here is saturated with water The ground here is saturated with water

and there is little oxygen, so decay takes and there is little oxygen, so decay takes place slowly. It has a surface inlet and place slowly. It has a surface inlet and outlet, and contains many invertebrates. outlet, and contains many invertebrates. It is also the breeding ground for many It is also the breeding ground for many ocean animals. Ex. crabs and shellfish.ocean animals. Ex. crabs and shellfish.

Mangrove ForestsMangrove Forests These are along warm, These are along warm,

tropical coasts where tropical coasts where there is too much silt for there is too much silt for coral reefs to grow. It is coral reefs to grow. It is dominated by salt-tolerant dominated by salt-tolerant trees called mangroves trees called mangroves (55 different species (55 different species exist). It also helps to exist). It also helps to protect the coastline from protect the coastline from erosion and provides a erosion and provides a breeding nursery for some breeding nursery for some 2000 species of fish, 2000 species of fish, invertebrates, and plants.invertebrates, and plants.

                                  

Importance of EstuariesImportance of Estuaries

Just one acre of estuary provides Just one acre of estuary provides $75,000 worth of free waste treatment, $75,000 worth of free waste treatment, and has a value of about $83,000 when and has a value of about $83,000 when recreation and fish for food are included. recreation and fish for food are included.

Prime Kansas farmland has a top value Prime Kansas farmland has a top value of $1,200 and an annual production of $1,200 and an annual production value of $600.value of $600.

The EvergladesThe Everglades

Southern Florida to the Southern Florida to the KeysKeys

ProblemsProblems As Miami develops, it encroaches on As Miami develops, it encroaches on

everglades. Plus, it prompts people vs. everglades. Plus, it prompts people vs. wildlife. It is freshwater and local areas wildlife. It is freshwater and local areas are draining it.are draining it.

RestorationRestorationBuild huge aqueduct, or find Build huge aqueduct, or find

other sources of fresh water an other sources of fresh water an protect it federally under protect it federally under endangered species act, etc.endangered species act, etc.

The Water The Water ResourceResource

ImportanceImportance Leonardo da Vinci said Leonardo da Vinci said

that “Water is the that “Water is the driver of nature.” driver of nature.” Without water, the Without water, the other nutrient cycles other nutrient cycles would not exist in their would not exist in their present forms, and present forms, and current forms of life on current forms of life on earth could not exist.earth could not exist.

Hydrogen BondsHydrogen Bonds

Attraction Between Attraction Between MoleculesMolecules

The strong forces of The strong forces of attraction between attraction between molecules of water.molecules of water.

Heat CapacityHeat Capacity Water changes temp very slowly Water changes temp very slowly

because it can store heat. This because it can store heat. This protects living organisms from the protects living organisms from the shock of abrupt temperature changes.shock of abrupt temperature changes.

Heat of VaporizationHeat of Vaporization

The temperature at which The temperature at which water turns to vapor.water turns to vapor.

Universal SolventUniversal Solvent

Water can Water can dissolve a wide dissolve a wide variety of variety of compounds. This compounds. This means it can means it can easily become easily become polluted by water-polluted by water-soluble wastes.soluble wastes.

                                                                    

Expansion When FrozenExpansion When Frozen

Ice has a lower density than Ice has a lower density than liquid water. Thus, ice liquid water. Thus, ice floats on water.floats on water.

Hydrologic CycleHydrologic Cycle

Surface WaterSurface Water

Examples – streams, rivers, and lakesExamples – streams, rivers, and lakes Source – precipitationSource – precipitation Watershed – Ex. small streams Watershed – Ex. small streams

larger streams larger streams rivers rivers sea sea

GroundwaterGroundwater Aquifers–porous rock w/ water flowing Aquifers–porous rock w/ water flowing

throughthrough Water Table – the level of earth’s land Water Table – the level of earth’s land

crust to which the aquifer is filledcrust to which the aquifer is filled Renewability – the circulation rate of Renewability – the circulation rate of

groundwater is slow (300 to 4,600 years).groundwater is slow (300 to 4,600 years).

Water UsageWater Usage Irrigation – watering cropsIrrigation – watering crops Industry – coolant (power plant)Industry – coolant (power plant) Domestic and Municipal – drinking, Domestic and Municipal – drinking,

sewage, bathwater, dishwater & sewage, bathwater, dishwater & laundrylaundry

ProblemsProblems

Too Much WaterToo Much WaterProblems include flooding, Problems include flooding,

pollution of water supply, and pollution of water supply, and sewage seeping into the sewage seeping into the ground.ground.

Too Little WaterToo Little Water

ExamplesExamples

Examples include drought Examples include drought and expanding deserts.and expanding deserts.

Overdrawing Surface Overdrawing Surface WaterWater Lake levels drop, recreation use Lake levels drop, recreation use

drops, fisheries drop, and salinization drops, fisheries drop, and salinization occurs. Ex. Soviet Union (Aral Sea); occurs. Ex. Soviet Union (Aral Sea); the inland sea drained the river that the inland sea drained the river that fed into it. Now it’s a huge disaster fed into it. Now it’s a huge disaster (read pg. 305 in text).(read pg. 305 in text).1964 1997

Aquifer DepletionAquifer Depletion

This harms endangered This harms endangered species, and salt water can species, and salt water can seep in.seep in.

Salinization of Irrigated Salinization of Irrigated SoilSoilWater is poured onto soil and Water is poured onto soil and

evaporates. Over time, as this evaporates. Over time, as this is repeated, nothing will grow is repeated, nothing will grow there anymore.there anymore.

U.S. Water U.S. Water ProblemsProblems

Surface Water ProblemsSurface Water Problems

The polluted Mississippi River (non-source The polluted Mississippi River (non-source point pollution) has too much point pollution) has too much phosphorus. phosphorus.

In the Erie Canal, which connects the In the Erie Canal, which connects the ocean to the Great Lakes, lampreys came ocean to the Great Lakes, lampreys came in and depleted the fish. The zebra in and depleted the fish. The zebra mollusk is also a problem in the Great mollusk is also a problem in the Great Lakes.Lakes.

Mono LakeMono Lake(like the Dead Sea) This has a (like the Dead Sea) This has a

huge salt concentration due to huge salt concentration due to man’s draining.man’s draining.

Colorado River BasinColorado River Basin These are dams & These are dams &

reservoirs that feed reservoirs that feed from the Colorado from the Colorado River all the way to River all the way to San Diego, LA, Palm San Diego, LA, Palm Springs, Phoenix & Springs, Phoenix & Mexico. So far has Mexico. So far has worked because worked because they haven’t they haven’t withdrawn their full withdrawn their full allocations. See allocations. See pg306. pg306.

Groundwater ProblemsGroundwater Problems

These include pollution, These include pollution, salt, and draining too much.salt, and draining too much.

Ogallala AquiferOgallala Aquifer

This is the world’s largest known aquifer, This is the world’s largest known aquifer, and fuels agricultural regions in the U.S. It and fuels agricultural regions in the U.S. It extends from South Dakota to Texas. It’s extends from South Dakota to Texas. It’s essentially a non-renewable aquifer from essentially a non-renewable aquifer from the last ice age with an extremely slow the last ice age with an extremely slow recharge rate. In some cases, water is recharge rate. In some cases, water is pumped out 8 to 10 times faster than it is pumped out 8 to 10 times faster than it is renewed. Northern states will still have renewed. Northern states will still have ample supplies, but for the south it’s ample supplies, but for the south it’s getting thinner. It is estimated that ¼ of getting thinner. It is estimated that ¼ of the aquifer will be depleted by 2020. the aquifer will be depleted by 2020.

Global Water Problems

Stable RunoffStable Runoff As water runs off from rain, it’s supposed As water runs off from rain, it’s supposed

to get into rivers, and finally off to the to get into rivers, and finally off to the sea. But when we dam rivers, less goes sea. But when we dam rivers, less goes to the ocean, meaning the brackish water to the ocean, meaning the brackish water (where the river hits the ocean) becomes (where the river hits the ocean) becomes more salty. This is the breeding ground more salty. This is the breeding ground for many fish and invertebrates. This for many fish and invertebrates. This harms the ecology of the area.harms the ecology of the area.

Drinking Water Drinking Water ProblemsProblems

Coliform BacteriaColiform Bacteria

The W.H.O. recommends there The W.H.O. recommends there be zero colonies of bacteria per be zero colonies of bacteria per 100ml of drinking water and 200 100ml of drinking water and 200 colonies per 100ml of swimming colonies per 100ml of swimming water. The average human water. The average human excretes 2 billion organisms per excretes 2 billion organisms per day (see how easily untreated day (see how easily untreated sewage can contaminate sewage can contaminate water?).water?).

Oxygen Demanding Oxygen Demanding WastesWastes

These are organic wastes that These are organic wastes that can be decomposed by aerobic can be decomposed by aerobic bacteria (causes lack of oxygen). bacteria (causes lack of oxygen). Fish die as a result of a lack of Fish die as a result of a lack of oxygen.oxygen.

Water-Soluble Inorganic Water-Soluble Inorganic ChemicalsChemicals

These include acids, salts, These include acids, salts, mercury, and lead. They make mercury, and lead. They make water unfit to drink.water unfit to drink.

Organic MaterialOrganic Material

These include oil, gas, These include oil, gas, plastics, pesticides, and plastics, pesticides, and detergents.detergents.

Population GrowthPopulation GrowthProblems include over-Problems include over-

drawing fresh water, drawing fresh water, pollution, and over-building pollution, and over-building so that water can’t seep so that water can’t seep into the ground.into the ground.

Sharing Water ResourcesSharing Water Resources

There are water wars out west. There are water wars out west. California bought the water from California bought the water from the Colorado River, but Arizona the Colorado River, but Arizona wants it. Who owns it? The same wants it. Who owns it? The same thing is happening in Texas. More thing is happening in Texas. More water rights are sold than the water rights are sold than the actual amount of water. How do actual amount of water. How do you share water? This is a you share water? This is a problem all over the world.problem all over the world.

Water Management

Dams and ReservoirsDams and Reservoirs

•Description: A dammed stream that can capture & store water from rain & melted snow.

•Benefits: Hydroelectric power; provides water to towns; recreation; controls floods downstream

• Problems: Reduces downstream flow; prevents water from reaching the sea (Colorado River) devastates fish life; reduces biodiversity.

Water DiversionWater Diversion

•Description: Damming a river to control where the water flows

•Benefits: Keeps water where we want it- cities!

•Problems: Drains wetlands, destroys land

DesalinizationDesalinization

•Description: Removing salt from salt water

•Benefits: Freshwater

•Problems: Uses lots of energy; costs 3-5X’s more money; what do we do with the salt?

Harvesting IcebergsHarvesting Icebergs

•Description: Towing massive icebergs to arid coastal areas (S. California; Saudi Arabia)

•Benefits: freshwater

•Problems: Technology not available; costs too high; raise temperatures around the earth.

ConservationConservation

•Description: Saving the water we have

•Methods: recycling; conserving at home; xeriscaping; fix leaks

•Benefits: Saves money; Saves Wildlife

•Problems: bothersome to people; lack of caring; laziness

Fishing Problems & Fishing Problems & TechniquesTechniques

The major decline in the worldwide The major decline in the worldwide catch of fish since 1990 is because catch of fish since 1990 is because of over-fishing.of over-fishing.

By-catch- fish or animals that were By-catch- fish or animals that were not meant to be caught.not meant to be caught.

Purse SeinesPurse Seines

Purse SeinesPurse Seines

A large purse-like net is put into A large purse-like net is put into the ocean and is then closed like a the ocean and is then closed like a drawstring purse to trap the fish. drawstring purse to trap the fish.

Tuna is a fish typically caught in Tuna is a fish typically caught in purse seinespurse seines

Dolphins are a by-catch of purse Dolphins are a by-catch of purse seinesseines

Long-line fishingLong-line fishing

Lines are put out that can be up to Lines are put out that can be up to 80 miles long w/ thousands of baited 80 miles long w/ thousands of baited hooks on them. These are left out hooks on them. These are left out free-floating for days and then the free-floating for days and then the boat comes back and picks them up. boat comes back and picks them up.

Pilot whales, dolphins, sea turtles, Pilot whales, dolphins, sea turtles, and birds are by-catch of this and birds are by-catch of this technique.technique.

Drift-net fishingDrift-net fishing

Each net hangs as much as 50 feet below Each net hangs as much as 50 feet below the surface and up to 34 miles long. the surface and up to 34 miles long.

Anything that comes into contact w/ these Anything that comes into contact w/ these nearly invisible nets are entangled. nearly invisible nets are entangled.

This leads to overfishingThis leads to overfishing Many unwanted fish and marine Many unwanted fish and marine

mammals, turtles and seabirds are caught.mammals, turtles and seabirds are caught.